In the Linux kernel, the following vulnerability has been resolved:
tcp: add sanity tests to TCP_QUEUE_SEQ
Qingyu Li reported a syzkaller bug where the repro
changes RCV SEQ after restoring data in the receive queue.
mprotect(0x4aa000, 12288, PROT_READ) = 0
mmap(0x1ffff000, 4096, PROT_NONE, MAP_PRIVATE|MAP_FIXED|MAP_ANONYMOUS, -1,
0) = 0x1ffff000
mmap(0x20000000, 16777216, PROT_READ|PROT_WRITE|PROT_EXEC,
MAP_PRIVATE|MAP_FIXED|MAP_ANONYMOUS, -1, 0) = 0x20000000
mmap(0x21000000, 4096, PROT_NONE, MAP_PRIVATE|MAP_FIXED|MAP_ANONYMOUS, -1,
0) = 0x21000000
socket(AF_INET6, SOCK_STREAM, IPPROTO_IP) = 3
setsockopt(3, SOL_TCP, TCP_REPAIR, [1], 4) = 0
connect(3, {sa_family=AF_INET6, sin6_port=htons(0), sin6_flowinfo=htonl(0),
inet_pton(AF_INET6, “::1”, &sin6_addr), sin6_scope_id=0}, 28) = 0
setsockopt(3, SOL_TCP, TCP_REPAIR_QUEUE, [1], 4) = 0
sendmsg(3, {msg_name=NULL, msg_namelen=0,
msg_iov=[{iov_base=“0x0000000000000003\0\0”, iov_len=20}], msg_iovlen=1,
msg_controllen=0, msg_flags=0}, 0) = 20
setsockopt(3, SOL_TCP, TCP_REPAIR, [0], 4) = 0
setsockopt(3, SOL_TCP, TCP_QUEUE_SEQ, [128], 4) = 0
recvfrom(3, NULL, 20, 0, NULL, NULL) = -1 ECONNRESET (Connection reset
by peer)
syslog shows:
[ 111.205099] TCP recvmsg seq # bug 2: copied 80, seq 0, rcvnxt 80, fl 0
[ 111.207894] WARNING: CPU: 1 PID: 356 at net/ipv4/tcp.c:2343
tcp_recvmsg_locked+0x90e/0x29a0
This should not be allowed. TCP_QUEUE_SEQ should only be used
when queues are empty.
This patch fixes this case, and the tx path as well.
OS | Version | Architecture | Package | Version | Filename |
---|---|---|---|---|---|
ubuntu | 18.04 | noarch | linux | < any | UNKNOWN |
ubuntu | 20.04 | noarch | linux | < any | UNKNOWN |
ubuntu | 18.04 | noarch | linux-aws | < any | UNKNOWN |
ubuntu | 20.04 | noarch | linux-aws | < any | UNKNOWN |
ubuntu | 18.04 | noarch | linux-aws-5.4 | < any | UNKNOWN |
ubuntu | 16.04 | noarch | linux-aws-hwe | < any | UNKNOWN |
ubuntu | 20.04 | noarch | linux-azure | < any | UNKNOWN |
ubuntu | 14.04 | noarch | linux-azure | < any | UNKNOWN |
ubuntu | 16.04 | noarch | linux-azure | < any | UNKNOWN |
ubuntu | 18.04 | noarch | linux-azure-4.15 | < any | UNKNOWN |
git.kernel.org/linus/8811f4a9836e31c14ecdf79d9f3cb7c5d463265d (5.12-rc3)
git.kernel.org/stable/c/046f3c1c2ff450fb7ae53650e9a95e0074a61f3e
git.kernel.org/stable/c/319f460237fc2965a80aa9a055044e1da7b3692a
git.kernel.org/stable/c/3b72d5a703842f582502d97906f17d6ee122dac2
git.kernel.org/stable/c/3bf899438c123c444f6b644a57784dfbb6b15ad6
git.kernel.org/stable/c/8811f4a9836e31c14ecdf79d9f3cb7c5d463265d
launchpad.net/bugs/cve/CVE-2021-4442
nvd.nist.gov/vuln/detail/CVE-2021-4442
security-tracker.debian.org/tracker/CVE-2021-4442
www.cve.org/CVERecord?id=CVE-2021-4442